1. Appearance issues before plate-making
Generally, CTP plates are divided into inner and outer packaging. The outside is a corrugated box with packing tape, and the inner packaging is moisture-proof black wrapping paper. The plates are usually separated by lining paper. The main problems before we make the plate include white spots, dirty spots, bubbles, scratches, and horseshoe marks.
For "white spots", the causes and solutions.
During the production process, it occurs when applying photosensitive adhesive, which is a coating problem and can be solved by improving the coating process.
During the transportation process, friction between the lining paper and the layout can be caused. The logistics and lining paper can be improved, and the lining paper without paper powder and paper wool can be selected.
During the storage process, if the temperature in the warehouse is too high or the humidity is too high, the storage conditions can be improved.
For "dirty spots", the causes and solutions.
During the production process, coating problems or dirty spots on the rubber rollers can be caused by improving the coating and inspecting the production line to eliminate dirty spots.
For "bubbles", the causes and solutions.
During the production process, it occurs when applying photosensitive adhesive, which is a coating problem and can be solved by improving the coating process.
For "scratches and horseshoe marks", the causes and solutions.
During transportation, you should handle it with care to avoid external impact on the layout. It is best to transport it on a pallet.
2. Appearance problems after plate making and development
The CTP plate passes through the plate-making equipment and the developing equipment can be printed on the printing press. Observe the layout to see if there are fingerprints, scratches, streaks, dirty spots, white spots, etc.
For "fingerprints", the causes and solutions.
During the plate production process, the drying temperature is not high enough, the plate is too tender, or there is dirt on the fingers or sweat stains sticking to the plate when taking the plate. In this case, you should wear gloves when taking the plate or the plate with the backing paper.
For "scratches", the causes and solutions.
The conveyor facilities of the plate-making machine may be caused by the developing machine. You can check and clean the conveying facilities of the plate-making machine and check whether the transmission of each roller and brush in the developing machine is normal and whether there are any defects.
For "series", the causes and solutions.
It is usually caused by abnormal development. Check and adjust the development concentration, temperature, plate speed, and pressure of each roller and brush in the development machine.
For "dirty spots", the causes and solutions.
During the production process, if the holes are not sealed or there are insoluble impurities in the photosensitive adhesive, the production process should be improved and the quality inspection should be checked.
It occurs during development because the developer solution is not effective enough, the water pressure in the washing process is not enough, or the pressure of the rubber roller or brush is not enough. The concentration of the developer should be adjusted, or the temperature should be increased, the plate running speed should be reduced, the water pressure should be increased, and the appropriate rubber roller and brush pressure should be adjusted.
Suppose the exposure of the plate-making equipment is insufficient or the focus is not accurate enough. In that case, you can adjust the focus value of the equipment, increase the exposure, reduce the rotation speed, etc.
For "white spots (of the network)", the causes and solutions.
If the development is unstable, you can adjust the parameters of the developer and adjust the pressure of the brush and rubber roller to solve the problem.
The lining paper is damp and scratched. It is recommended to replace the lining paper to prevent the lining paper from getting damp.
Huida Print-All Technology company is an advanced and professional manufacturer of printing plates, mainly selling CTP, CTCP, and PS plates as well as offering ODM/OEMs, especially for the offset. For more information, please click the official website link here: https://www.huidaoffsetplate.com/.